The present invention relates to a disposable carton for food products or the like and more particularly to a carton formed from lid and tray members which includes a bottom locking means between the lid and tray which is readily released.
The manufacture of disposable food cartons particularly for the fast food industry involves highly developed technology. Such cartons must be designed for maximum economy and utility with emphasis on ease of handling, filling and closing. Product identification, storage of unused cartons and integrity after being filled are also important. When such cartons are used for packaging hot foods, design considerations must be incorporated into the carton structure to provide a quick and easy means for loading and closing the carton lids to keep the foods hot and for retaining the lids in a closed condition until they are served. Conversely, the means for retaining the lids closed must be readily releasible by the consumer when the foods are to be consumed. Preferably the means for retaining the lids closed should be automatically engaged upon closing and released merely with the application of pressure to some portion of the carton.
There are many teachings in the prior art for locking the lids and trays of cartons together. However, in most cases, the closures cannot be automatically engaged, but require a separate mechanical action to align the locking elements together, or, one or more of the locking elements must be bent from its normal plane before it can be utilized. One example of an effective automatic lock for such cartons is disclosed in U.S. Pat. No. 4,516,718 owned by the present assignee. However, the locking means disclosed in the aforementioned patent is positive and not readily released.